Immunization with DNA

I would like to ask a series of questions on "naked DNA" (expression vector
plasmid) vaccination and immunization.(For those not aware of the technique
there is a nice review in The Journal of Immunological Methods (1994) 176,
by Donnelly et al.) This seems to be such an extraordinarily successful
technique (and I am such a sceptic) that it would be interesting to hear
from someone who could define some of its disadvantages. There is always
the possibility, however remote, that the vector promoter will integrate
into the host genome and cause all sorts of problems. Do you think that
this is an insurmountable objection to the commercial use of this
technique? What are the other roadblocks that may prevent use of DNA
vaccines (human or veterinary) in the near future? Most of the articles on
the subject have an industrial partnership, but does anyone know who owns
the patent rights? Lastly, there appears to be no common key-word to pull
out the articles from a data base: any suggestions?
Thanks
BGT
Sherbrooke
B.G.T.